Of the two, Tempo. But prob the VFs would be better, unless you like the firmer React foam under the heel.
I ran the only 50k of my life a couple of months ago. There were a couple of runners in the Nike Invincible in both the 50k and a 100k - I was surprised, because otherwise it was mainly Altra and VFs.
For a LSD run, Invincibles are excellent because they're so soft. Your legs are so protected. They have also the ability to be surprisingly fast, because of the ZoomX - I think way more so than people expect because it isn't the intended purpose. But, I found that in order to get up to speed, and increase turnover, your Achilles suffer. It is a bit bulky and an awkward shape to maintain form - maybe a 5k but a marathon would be a headache - in my opinion. It has a 9mm drop, but it yields so much on impact (not having a plate) when you really push it, that it negates the drop - your foot buries in the midsole. It also yields laterally, and is unstable. - not a good combo with tiring and form suffering towards the latter half. So unless you are only thinking of covering the distance and cruising without time concerns, it wouldn't be my race choice. If you're thinking about 3:30-4hrs, then it may be an option - but wouldn't buy specifically for this.
I have no idea how those guys did in the 50k with them, but I know the guys on the podium, and the guys who kept passing me on the looped course, were in Vaporflys. I was giving a final send-off to a pair of Pegs.